1. Field of Invention
The present invention relates to a product used in oral cavity, and more particularly, to a Lactobacillus paracasei-containing product used for inhibiting dental diseases caused by bacteria.
2. Related Art
A dental caries is one of multi-factorial diseases caused by the following factors, including constituted element of teeth, configuration, position, component of saliva, pH value, secretion, viscosity, anti-bacterial factors, carbohydrate level in diet, fluoride, and microorganisms and their physical properties. Therefore, reducing the number of bacteria in oral cavity may reduce the occurrence of periodontal diseases caused by dental caries and bacteria. Generally, the bacteria affecting the health care of teeth are all in the form of a dental plaque, which is a film-shaped substance adhered on a surface of teeth in the oral cavity, with the appearance being gradually changed from a transparent appearance into a white deposit. The bacteria in the dental plaque include a variety of cocci, bacilli, and leptothrix, wherein the main bacteria of dental plaques that most easily causes dental caries or a periodontal inflammation include Streptococcus mutans, Streptococcus sanguis, Actinomyces viscosus, Streptococcus sobrinus, and Porphyromonas gingivalis. 
Currently, many researching results show that, special probiotics can reduce the occurrence of dental caries, and also decrease the number of the Streptococcus mutans of dental caries in oral cavity, which further reduces the formation of dental plaques so as to decrease a seedbed for pathogens of periodontal disease, and thereby preventing gingivitis and bone loss of an inferior alveolar bone caused by the toxin of bacteria, and reducing the occurrence of periodontal diseases. For example, a study in Japan has found that a Lactobacillus salivarius (LS1) may be used to effectively prevent dental caries. Additionally, in Helsinki University of Holland, children at the age of 1-6 who have administered milk added with lactobacilli in a long term for preventing dental caries are studied; and, young people who have administered cheeses added with a special probiotic in a short term for preventing dental caries are also studied. The result shows that the number of Streptococcus mutans in saliva is reduced by approximately 20% after 3 weeks. Furthermore, a study in Mexico also shows that continually chewing a chewing gum containing lactobacilli treated by heat sterilization once a week for 16 weeks may improve dental caries and reduce the occurrence of dental caries by approximately 42%.
Additionally, several kinds of lactobacillus cultures for inhibiting the formation of the dental plaque are disclosed in U.S. Pat. No. 6,036,952, which include Enterococcus spp. 1357, Lactobacillus acidophilus V20, and Lactococcus lactis 1370. In addition, a product containing lactobacillus cultures of ATTC PTA-4965 and PTA-4964 is disclosed in U.S. Pat. No. 6,872,565, which is used for inhibiting dental caries caused by bacteria. The inhibition effect achieved by combining the ATTC PTA-4965 or PTA-4964 and an oral mucin or the dental plaque is used for effectively reducing the number of Streptococcus mutans. Alternatively, a method of treating and preventing dental caries, dental plaques, and periodontal diseases with lactobacillus cultures CNCM I-1984, CNCM I-1985, CNCM I-1986, CNCM I-1987, or LMG P-18997 is disclosed in U.S. Pat. No. 6,942,849, wherein the lactobacilluscultures are genetically modified to enhance the viscosity for a tooth surface film.
Currently, it is found that, Lactobacillus paracasei may be used to promote an immunocyte to release a number of interferon, which is helpful for improving allergic diseases. Human immunocyte T lymphocytes are divided into two types according to the secreted different cytokines, wherein there is a dynamic balance between Type I and Type II T lymphocytes, and both of them are influenced by each other, thereby affecting the result of a reaction of the whole immune system to an antigen. If the reaction of Type II T lymphocyte is excessively strong, an allergic symptom occurs to a patient. The allergy may be prevented by increasing the activity of Type I T lymphocyte or inhibiting the activity of Type II T lymphocyte. When the Lactobacillus paracasei is used in human bowel, due to the difference of cell walls and cell contents, the Lactobacillus paracasei significantly promotes the activity of Type I T lymphocyte and further inhibits the effect of Type II T lymphocyte, and thus preventing allergy.
To sum up, a variety of lactobacilli are now found to have the function of inhibiting dental caries, dental plaques, and periodontal diseases. The Lactobacillus paracasei has been used in human bowel in the past to relieve the body allergic symptom after being absorbed by the bowel. However, the efficacy that the Lactobacillus paracasei is used in oral cavity to prevent dental diseases has not been found yet.